diff --git a/include/ctpg/ctpg.hpp b/include/ctpg/ctpg.hpp
index 9ff5905..6631ecc 100644
--- a/include/ctpg/ctpg.hpp
+++ b/include/ctpg/ctpg.hpp
@@ -265,7 +265,7 @@ namespace stdex
                 data[i] |= other.data[i];
         }
 
-        constexpr bool operator == (const cbitset<N>& other)
+        constexpr bool operator == (const cbitset<N>& other) const
         {
             for (auto i = 0u; i < underlying_count; ++i)
                 if (data[i] != other.data[i])
diff --git a/tests/list_helpers.cpp b/tests/list_helpers.cpp
index 2a56542..d2947c7 100644
--- a/tests/list_helpers.cpp
+++ b/tests/list_helpers.cpp
@@ -38,6 +38,8 @@ namespace test
 {
     struct non_copyable_thing
     {
+        non_copyable_thing() = default;
+
         non_copyable_thing(const non_copyable_thing&) = delete;
         non_copyable_thing& operator = (const non_copyable_thing&) = delete;